AM625: ePWM Support in U-Boot for Backlight Control

Sakshi Koundal

Part Number: AM625

Tool/software:

Hi Team,

(Following up on a previous ticket: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1385447/am625-u-boot-epwm-support)

We need to enable ePWM in U-Boot on a custom AM625 board for DPI backlight control.

The device tree uses: epwm0: pwm@23000000 {

compatible = "ti,am64-epwm", "ti,am3352-ehrpwm";

However, we couldn't find any driver for "ti,am64-epwm" in U-Boot and "ti,am3352-ehrpwm" is not for am62x.

Could you please update on this and confirm which driver to use for enabling ePWM on AM625 in U-Boot?

4 months ago

0 Bin Liu 4 months ago

TI__Guru**** 170191 points

Hi, the domain expert is traveling this week, please expect delayed response.

0 Sakshi Koundal 4 months ago in reply to Bin Liu

Prodigy 90 points

Hi Bin,

Is there any update?

0 Nick Saulnier 4 months ago

TI__Guru** 102650 points

Hello Sakshi,

Thank you for your patience. I am checking with the developers for more information.

For my reference, what version of Linux and U-Boot are you using for your product?

Regards,

Nick

0 Sakshi Koundal 4 months ago in reply to Nick Saulnier

Prodigy 90 points

Hi Nick,

We are using Linux version 6.6.15 and U-boot version 2024.01

0 Nick Saulnier 4 months ago in reply to Sakshi Koundal

TI__Guru** 102650 points

Hello Sakshi,

I apologize for the continued delays here. It might be a couple more days before I can get any information. Please ping the thread if I have not responded by Monday or Tuesday.

Regards,

Nick

0 Praneeth Bajjuri 4 months ago in reply to Nick Saulnier

TI__Expert 6406 points

we don't support backlight for splash as AM62 SK doesn't support it (OLDI lines coming out of EVM are not carrying PWM data).

U-boot framework does support though as AM335x supports it

Further Ref: https://patchwork.ozlabs.org/project/uboot/list/?series=459071&state=%2A&archive=both

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AM625: ePWM Support in U-Boot for Backlight Control